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<table width="100%" summary="page for Sitka89"><tr><td>Sitka89</td><td align="right">R Documentation</td></tr></table>

<h2>
Growth Curves for Sitka Spruce Trees in 1989
</h2>

<h3>Description</h3>


<p>The <code>Sitka89</code> data frame has 632 rows and 4 columns.  It gives repeated
measurements on the log-size of 79 Sitka spruce trees, 54 of which
were grown in ozone-enriched chambers and 25 were controls.  The size
was measured eight times in 1989, at roughly monthly intervals.
</p>


<h3>Usage</h3>

<pre>
Sitka89
</pre>


<h3>Format</h3>


<p>This data frame contains the following columns:
</p>

<dl>
<dt><code>size</code></dt><dd><p>measured size (height times diameter squared) of
tree, on log scale.</p>
</dd>
<dt><code>Time</code></dt><dd><p>time of measurement in  days since 1 January 1988.</p>
</dd>
<dt><code>tree</code></dt><dd><p>number of tree.</p>
</dd>
<dt><code>treat</code></dt><dd><p>either <code>"ozone"</code> for an ozone-enriched
chamber or <code>"control"</code>.</p>
</dd>
</dl>



<h3>Source</h3>


<p>P. J. Diggle, K.-Y. Liang and S. L. Zeger (1994)
<EM>Analysis of Longitudinal Data.</EM>
Clarendon Press, Oxford
</p>


<h3>See Also</h3>


<p><code>Sitka</code>
</p>


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